Networking with VPC

Definition: A Virtual Private Cloud (VPC) is your own private, isolated network inside AWS. It controls how your resources connect to each other and to the internet.

Why a VPC?

You would not put every server directly on the open internet. A VPC lets you decide what is public (like a web server) and what is private (like a database), and how traffic flows between them — just like designing a secure office network.

The key pieces

• Subnets — sections of your network; public subnets reach the internet, private ones do not
• Security groups — virtual firewalls on each resource, controlling allowed ports and sources
• Internet & NAT gateways — how traffic gets in and out
• Route tables — the rules directing traffic

A common pattern

Put your web servers in a public subnet and your database in a private subnet. The web servers face the internet; the database is reachable only from inside the VPC — far safer.

💡 Takeaway: VPC is how you keep cloud resources organised and secure. Public for what users touch, private for everything sensitive.